Anastomosis, both vascular and recto-colic, is a well-known art that can be practiced by the use of mechanical devices and without resort to sewing sutures. For optimum results in the practice of the art, it is necessary to maintain patency of the lumina without undue stress of the lumen wall that could lead to tearing, spasm, and thrombosis and to maintain patency and minimize surgical time by reliance on anastomotic means that are minimal in bulk, simplified in structure, do not require sophisticated handling, and can be quickly assembled in surgery.
In these regards, as the following U.S. patents illustrate, the known art is wanting.
Zack, U.S. Pat. No. 2,453,056, performs a 180.degree. eversion of a substantial portion of a lumen wall about a tubular member and then uses two annular rings to separately clamp respective lumen walls to such member.
The recto-colic clamp of Sugarbaker, U.S. Pat. No. 2,638,901, is relatively ponderous, awkward to use, and requires threaded elements to maintain clamping.
Collito, U.S. Pat. No. 3,254,650, in a more convenient to use of the disclosed species, requires that impaling nails be clinched.
Schomacher, U.S. Pat. No. 4,233,981, complicates assembly in surgery by use of separate impaling elements and clamping means comprised of threaded members and separate nut means therewith.
Geroc, U.S. Pat. No. 4,294,255, discloses an anastomotic device requiring a pair of relatively sophisticated ring structures and separate pin means accommodated in each ring.
Daniel, U.S. Pat. No. 4,523,592, discloses barbed impaling elements that extend from opposed faces of associated ring elements and are adapted to each couple with an open-ended slot structure in the opposed face. The structure does not offer positive fixing since the slots are open-ended, and the barbs may slide free upon further handling, stress, or poor assembly.
Schenk et al., in a first anastomotic device disclosure, U.S. Pat. No. 4,624,255, requires use of a pneumatic means and, in a second disclosure, U.S. Pat. No. 4,693,249, complicates assembly by requiring manipulation of a split ring and the structurally awkward use of impaling means that extend normal to the edge surface of the ring and through unsupported lumenal wall sections, whereby the wall is relatively more apt to tear.
Liu et al., U.S. Pat. No. 4,747,407, requires sophistical handling and the use of clinching tools.